NEW YORK (Reuters) - A regional director for the securities industry's self-regulatory agency resigned several weeks after the organization received a letter revealing the official had pleaded guilty two decades ago to charitable bingo fraud.

The letter, which was reviewed by Reuters, was sent on May 21 by former securities broker David Evansen to Richard Ketchum, the chief executive officer of the Financial Industry Regulatory Authority and Susan Axelrod, FINRA's executive vice president of regulatory operations.

The four-page letter said Mitchell C. Atkins, who up until this week was a regional director and head of FINRA's District 7, which is based in Boca Raton, Florida, was indicted in 1993 in Louisiana "for felony theft and charitable bingo fraud."

The indictment by the 19th Judicial District in East Baton Rouge Parish was confirmed by the clerk's office for the East Baton Rouge Parish court.

Atkins pleaded guilty in December 1993 to one charge of charitable bingo fraud, according to a copy of court records reviewed by Reuters.

Court records reviewed by Reuters state that Atkins was sentenced in January 1994 to a year of probation, 100 hours of community service and $1,000 in fines for the bingo fraud.

Atkins, 42, who resigned from FINRA earlier this week, could not be reached for comment and FINRA declined to provide a forwarding contact phone number for him.

Nancy Condon, a spokeswoman for FINRA, said: "Mitch Atkins resigned to pursue other interests." She declined to comment on the letter.

Atkins' office oversees the work of brokers and brokerages working in southern states from Florida to Texas.

FINRA oversees securities brokers and investment advisers, maintaining a database of their registration and disciplinary statuses and handling customer disputes. It shares regulatory duties with the U.S. Securities and Exchange Commission and has the power to ban brokers and registered investment advisers from the industry.

Evansen said he had been banned from the brokerage business by FINRA. His publicly available broker's record indicated the ban was enacted in June, 2011 after Evansen failed to respond to a request for information. The record did not specify the nature of the request. Evansen said he is appealing the ban.

In his letter to the FINRA executives, Evansen described a whistleblower complaint he had filed with the SEC alleging fraud in a Texas-based financial clearinghouse.

"It was for no small purpose, that Mr. Atkins and FINRA, went to such lengths, to prevent the sunlight from illuminating the truth," Evansen wrote in his letter.